"How Long is a Piece of String":
Benjamin Green, Daniel Prince, Jerry S. Busby, David Hutchison · 2017
The numbers and severity of global cyber security attacks on Industrial Control Systems have increased over recent years. However, there are also significant efforts to improve defensive capabilities. While comprehensive reviews of risk assessment efforts exist, little detail is currently available on how they are being applied by security practitioners. This paper provides a summary of the approaches adopted by security practitioners, outlining key phases applied to risk assessment, application of existing predefined methodologies, and challenges faced throughout the overall process.